Associations between total serum GGT activity and metabolic risk: MESA

Abstract

Aim: To evaluate associations between total serum GGT activity, metabolic risk factors and prevalent metabolic disease in MESA. Patients & methods: Continuous associations between GGT and fasting blood glucose (FBG), fasting insulin, HbA1c and Homeostasis Model Assessment Index of Insulin Resistance (HOMA–IR) were evaluated in the entire MESA cohort and in metabolic disease subgroups using linear regression models incrementally adjusted for age, gender, site, race, lifestyle, traditional risk factors and medications. Cross-sectional odds of prevalent impaired FBG, metabolic syndrome and Type 2 diabetes were calculated for GGT quintiles in the entire cohort and in subgroups defined by age (< or ≥65 years) and ethnicity. Results: In multivariable models, significant associations were present between GGT activity and FBG, fasting insulin, HbA1c and HOMA–IR, with the interaction between GGT and BMI affecting the association between GGT and HOMA–IR as well as the association between BMI and HOMA–IR (p < 0.0001). Adjusted odds ratios (95% CIs) of prevalent impaired FBG, metabolic syndrome and Type 2 diabetes for quintile 5 versus 1 in the entire cohort were 2.4 (1.7–3.5), 3.3 (2.5–4.5) and 2.8 (1.8–4.4), respectively (p < 0.0001). GGT associations weakened with age. The significance of linear trends for increased prevalent metabolic disease by increasing GGT quintile varied by ethnicity. Conclusion: GGT is strongly associated with both cardiovascular and metabolic risk factors, including prevalent metabolic disease, in the MESA cohort.